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1.
Lake Sammamish has shown a decrease in its mean annual concentration of phosphorus following diversion of about one third of the external loading in 1968. During 1971–1975 the P concentration averaged 27 μg l−1, in contrast to the prediversion (1964–1966) concentration of 33 μg l−1, and may be equilibrating near the predicted steady state concentration of 22 μg l−1. Neither phytoplankton biomass or Secchi visibility has changed following diversion, however the blue green component of the phytoplankton decreased by nearly 50%. The failure of biomass and visibility to improve is probably a result of similar pre- and postdiversion winter spring epilimnetic P concentrations. The marked reduction in P since diversion occurred during and prior to fall overturn and may have represented a supply of P for later summer early fall blue green algal populations that declined after diversion.Runoff from a rapidly developing westside portion (18%) of the watershed is contributing substantially to P loading of the lake. Development to a density of about ten dwellings ha−1 has increased loading possibly on the order of 14%. Future development of the eastside portion (26% of watershed) may increase loading by 20% and be equivalent to nearly one half of the P previously diverted in 1968.  相似文献   
2.
空气节能器是美国大中型建筑全空气系统和空气-水系统中应用广泛的一种节能设备.ANSI/ASHRAE/IESNA Standard 90.1-2007规定,凡是带风机的冷却系统都应考虑使用空气侧或水侧节能器.介绍了空气节能器的组成、控制方式和4种运行模式,并指出空气节能器运行中容易出现的问题.鉴于我国的气候、大气污染状况及空调系统形式,认为目前空气节能器应用于我国大中型建筑的空调系统中的条件尚不成熟.  相似文献   
3.
Islet-brain 1 (IB1), a regulator of the pancreatic beta-cell function in the rat, is homologous to JIP-1, a murine inhibitor of c-Jun amino-terminal kinase (JNK). Whether IB1 and JIP-1 are present in humans was not known. We report the sequence of the 2133-bp human IB1 cDNA, the expression, structure, and fine-mapping of the human IB1 gene, and the characterization of an IB1 pseudogene. Human IB1 is 94% identical to rat IB1. The tissue-specific expression of IB1 in human is similar to that observed in rodent. The IB1 gene contains 12 exons and maps to chromosome 11 (11p11.2-p12), a region that is deleted in DEFECT-11 syndrome. Apart from an IB1 pseudogene on chromosome 17 (17q21), no additional IB1-related gene was found in the human genome. Our data indicate that the sequence and expression pattern of IB1 are highly conserved between rodent and human and provide the necessary tools to investigate whether IB1 is involved in human diseases.  相似文献   
4.
Fibronectin may contribute to asthma pathogenesis by recruitment and activation of inflammatory cells, and by promotion of subepithelial fibrosis. Fibronectin is produced by several types of airway cells, including epithelial cells, fibroblasts, and alveolar macrophages. To test the hypothesis that antigen-induced airway inflammation is associated with increased local generation of fibronectin, segmental bronchoprovocation (SBP) with antigen and saline was performed in 17 atopic patients. Bronchoalveolar lavage (BAL) was performed at 5 min and 48 h after segmental challenge with saline or antigen. Fibronectin concentrations in BAL fluid, measured by enzyme-linked immunosorbent assay (ELISA), increased more than 5-fold 48 h after antigen challenge (65 [47 to 110] versus 407 [240 to 697] ng/ml, median and 25 to 75% interquartiles, p < 0.05). Fibronectin concentrations 48 h after antigen challenge correlated with histamine concentrations 5 min after antigen challenge and numbers of eosinophils, neutrophils, macrophages, and total cells in BAL fluid 48 h after antigen challenge. BAL was more enriched in fibronectin 48 h after challenge than would be predicted solely from increased permeability of plasma proteins. Western blot analysis showed that fibronectin in BAL fluid was largely intact and contained the extra domain-A (ED-A) splice variant of cellular fibronectin, indicative of local production. We conclude that antigen challenge in atopic subjects causes increased production of fibronectin by airway cells and speculate that this response may contribute to airway remodeling in allergic inflammation.  相似文献   
5.
A pump suitable for use with gas electrodes, in which recirculation of the gas is necessary, is described. The system to which the cell with the gas electrode and the pump are connected does not change its volume when the pump is in operation. The pump works as follows: an embolus, consisting of a Tefloncoated magnetic stirring bar, placed inside a glass tube having an internal diameter slightly larger than the diameter of the bar, is moved from the outside with a permanent magnet, which in turn is moved horizontally along the tube by means of a mechanical assembly driven by an electric motor. The motion of the embolus is accompanied by the closing and opening of glass valves which allow the gas to circulate in the desired direction. The pump, used in conjunction with a vacuum line, operates from pressures as low as 60 Torr to above atmospheric pressure. The operation of the pump is unaffected by organic gases and most inorganic gases.  相似文献   
6.
We propose that intracellular prostaglandins (PGs) are essential for the final expression of the effects of second messengers in most cells. We suggest that the amounts of PGs required are very small (in the picomolar range) and are much lower than those used in most current PG studies. We suggest that while therapeutic levels of inhibitors of PG synthetase may be adequate to block the overflow of PGs from cells, they are in most cases unlikely to reduce intracellular PGs sufficiently to test the role of such PGs. We propose that there is a basal level of PG synthesis unaffected by hormones but that above this level PG synthesis is regulated by the interplay between physiological levels of cortisol, prolactin, growth hormone and thyroid hormones. For the most part prolactin seems to stimulate PG synthesis and cortisol to inhibit it: cortisol has, however, no inhibitory effect on basal PG synthesis. In reducing prolactin-stimulated PG synthesis cortisol is 1000-2000 times more potent than indomethacin on a molar basis. We suggest that the regulation of intracellular PG levels is the mechanism of the so-called "permissive" actions of these hormones. These concepts could prove important in the understanding of many aspects of physiology and pathophysiology including diurnal and seasonal changes in hormone responsiveness. They are also relevant to the use of established drugs and the design of new ones.  相似文献   
7.
Leukemic reticuloendotheliosis (LRE) or "hairy cell leukemia" is a unique form of leukemia which possesses features of both a chronic and acute leukemia. Its characteristic morphology, clinical diagnosis, and treatment are discussed. A high index of suspicion should make this entity easily diagnosed by the medical technologist.  相似文献   
8.
Teams engaging in assistive technology research should include expertise in the domain of disability itself, in addition to other areas of expertise that are more typical in human–computer interaction (HCI) research, such as computer science and psychology. However, unexpected problems can arise when HCI researchers do not adequately plan the involvement of domain experts in a research project. Although many research teams have included domain experts when designing assistive technologies, there has been little work published on how to best involve these experts in the research process. This paper is a first step towards filling that void. Based on the authors’ own experiences involving domain experts in research, as well as those documented in the literature, five types of domain experts and three broad roles that domain experts can play are identified, and five guidelines for their involvement are presented. This analysis will be useful to anyone in the assistive technology and universal accessibility communities, especially those who are in the early stages of conducting research in this area. It is intended to lay the foundation of best practices for involving domain experts in assistive technology research.  相似文献   
9.
Schizophrenic patients are extremely heavy tobacco smokers. However, a lower incidence of lung cancer in schizophrenic patients has been observed in comparison to other heavy smokers. Nicotine increases the proliferation of pulmonary neuroendocrine tissue, causing the release of a bombesin-like peptide. Thus, bombesin-like peptide levels in urine may be an indicator of precancerous, cigarette-induced lung damage. Bombesin-like peptide levels of 10 schizophrenic smokers and 11 schizophrenic nonsmokers were compared to those of nonschizophrenic subjects matched for age and pack-years of smoking. The nonschizophrenic smokers showed the expected increase in urinary bombesin-like peptide levels, as compared to nonschizophrenic nonsmokers. Schizophrenic patients had lower bombesin-like peptide levels independent of smoking effects. The mechanism of the difference in bombesin-like peptide levels between schizophrenic patients and nonschizophrenic subjects is unknown, but one possibility involves alteration in the alpha 7-nicotinic acetylcholine receptor, which mediates the growth of some neuroendocrine cell lines in vitro.  相似文献   
10.
Canola oil is not presently permitted in infant formulations in the United States because of lack of information concenring the effects of feeding canola oil to the newborn. We have previously reported a transient decrease in platelet counts and an increase in platelet size in newborn piglets fed canola oil for 4 wk, and have confirmed this in the present study. In canola oil-fed piglets, changes in platelet size and number were overcome by adding either long-chain saturated fatty acids from cocoa butter (16:0 and 18:0), or shorter-chain saturates from coconut oil (12:0 and 14:0). Feeding a high erucic acid rapeseed (HEAR) oil, with 20% 22:1n−9, led to an even greater platelet reduction and increased platelet size throughout the 4-wk trial. Bleeding times were longer in piglets fed canola oil or HEAR oil compared to sow-reared and soybean oil-fed piglets. There were no other diet-related changes. Diet-induced platelet changes were not related to platelet lipid class composition, but there were fatty acid changes. The incorporation of 22:1n−9 into platelet phospholipids of piglets fed canola oil was low (0.2–1.2%), and even for the HEAR oil group ranged from only 0.2% in phosphatidylinositol to 2.4% in phosphatidylserine. A much greater change was observed in the concentration of 24:1n−9 and in the 24:1n−9/24:0 ratio in platelet sphingomyelin (SM). The 24:1n−9 increased to 49% in the HEAR oil group compared to about 12% in animals fed the control diets (sow-reared piglets and soybean oil-fed group), while the 24:1n−9/24:0 ratio increased from about 1 to 12. Even feeding canola oil, prepared to contain 2% 22:1n−9, led to a marked increase in 24:1n−9 to 29% and had a 24:1n−9/24:0 ratio of 5. The canola oil/cocoa butter group, which also contained 2% 22:1n−9, showed a lower level of 24:1n−9 (20%) and the 24:1n−9/24:0 ratio (3) compared to the canola oil group. The results suggest that the diet-related platelet changes in newborn piglets may be related to an increase in 24:1n−9 in platelet SM, resulting from chain elongation of 22:1n−9. The inclusion of canola oil as the sole source of fat in the milk-replacer diets of newborn piglets resulted in significant platelet and lipid changes.  相似文献   
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